MEDICAL IMAGING: America wakes up to 3-D human coronary artery imaging

Dr. Tim Johnson, Medical Editor for ABC’s Good Morning America show, said he is “amazed” by the “unbelievable imagery” enabled by optical frequency-domain imaging (OFDI), an advance over optical coherence tomography (OCT) that is giving researchers their first-ever detailed look at the interior of human coronary arteries. Johnson featured the technique recently, following its presentation in the journal JACC: Cardiovascular Imaging.

“We expect to see commercial devices available in a one- to two-year time frame,” says Brett Bouma of the Wellman Center for Photomedicine at Massachusetts General Hospital (MGH), where the technique was developed.

While OCT examines tissues one point at a time, OFDI can look at more than 1000 points simultaneously. The approach gives three-dimensional, microscopic views of significant segments of patients’ coronary arteries. “The wealth of information that we can now obtain will undoubtedly improve our ability to understand coronary artery disease and may allow cardiologists to diagnose and treat plaque before it leads to serious problems,” says Dr. Gary Tearney of the MGH Pathology Department and the Wellman Center.

A recent study enrolled three patients scheduled to have stents placed in their coronary arteries; during the surgery, immediately following stent placement, OFDI was used to image 3- to 7-cm-long segments of the patients’ coronary arteries including the stented areas. OFDI provided detailed images along the length of the arteries—visualizing lipid or calcium deposits, immune cells that could indicate inflammation, and the stents. With post-processing, they were also able to produce dramatic “fly-through” views looking down the artery’s interior. Tearney told BioOptics World that the team has just begun a test-retest reproducibility study at Erasmus Medical Center in the Netherlands to image the arteries of patients over time.

Tearney also noted that it will take two to three years for processors to advance enough to enable real-time 3-D reconstruction of the data. For the future, he says, incorporating intravascular ultrasound into the probe might enable deeper imaging.